1. Field of the Invention
The present invention relates to an input device including a switch unit.
2. Description of the Related Art
As in Japanese Unexamined Patent Application Publication No. 2001-222923, in a switch unit of an input device of the related art, when a button is pressed, a movable contact comes into contact with a set of fixed contacts and enters a contact state, and when the button is released, the movable contact is separated from the set of the fixed contacts and enters a separation state. However, in the switch unit of the related art, there is a disadvantage in that, when foreign matter or moisture is attached between the fixed contacts, the fixed contacts are short-circuited, and the movable contact is erroneously determined to be in the contact state even though the button is not pressed.
If two switch units are provided in the input device in order to solve the disadvantage, abnormality can be detected when inputs from the two switch units are different.
However, even in a case in which two switch units are provided, it cannot be known which of two states is correct in a case in which abnormality is detected. Therefore, it is necessary for the input device as well as another device having the input device mounted thereon to be stopped. In fact, there is a disadvantage in which there is a device in which it is difficult for an operation to be stopped immediately, and convenience is impaired when an operation of the input device or a peripheral device should be stopped in a case in which abnormality is detected.
Further, there is a disadvantage in that an occupied area of the input device increases if two switch units are provided.